821: exchequer Mar 8, 2017

It might be surprising that the word, 'exchequer'—denoting a national treasury—comes from a medieval Latin word meaning, 'chessboard', although you may know more if you are aware of the origins of 'checkmate', which you can see down below. While in Latin, and even earlier, the initial sense did in fact reference the game, the patterning of the board became associated with, among other things, accounting. Those employed to look over England's royal revenues after the Norman invasion—called 'Exchequer'—were so named for the tablecloth over tables on which they kept records. While the Latin word, 'scaccarium', meaning 'chessboard, and even the Old French 'eschequier' which gave English the word in question today are both spelt with S's, the spelling was changed to resemble the common Latin prefix, 'ex-' meaning, ‘out’ even though it bears no meaning.

'checkmate' and 'check'